1. Filed of the Invention
The present invention relates to a method and an apparatus for transferring image data from a terminal to an image server, and to a computer-readable recording medium storing a program to cause a computer to execute the method.
2. Description of the Related Art
When image data stored in an image server are transferred based on transfer request by a client, the client receives and decompresses the data to reproduce an image if the image data have been compressed based on a predetermined coding algorithm.
Meanwhile, as a format for storing image data, various formats such as JPEG, GIF, and TIFF are used. Recently, another format has been proposed. According to this format, image data are stored by being decomposed into a hierarchy based on resolutions or density resolutions (bit resolutions) and data at each level of the hierarchy (hierarchical data) are stored after coding and compression thereof. More specifically, image data are decomposed into the hierarchical data according to multiple resolutions or density resolutions through wavelet transform or the like, and the hierarchical data at each resolution or density resolution are coded according to the hierarchy and saved in a file after compression thereof.
This storing method has the following characteristics:
(1) Unlike a DCT (Discrete Cosine Transform) method used in the conventional JPEG format, no artifacts such as block distortion are created, since image data are not processed for each block.
(2) Only resolution information which is necessary for transfer of image data needs to be transferred, since the image data are coded hierarchically. This enables efficient image transfer.
(3) Various kinds of image processing such as frequency enhancing processing can be carried out comparatively easily, since image data are decomposed into the data at multiple resolutions or density resolutions.
(4) Simultaneous decomposition of space and frequency according to multiple-resolution analysis is possible. In a low frequency range wherein coding efficiency is greatly affected, an orthogonal transform can be carried out in a wide range, whereas in a high frequency range, an orthogonal transform is possible in a narrow range. Therefore, even when quantization noise is generated near an edge of an image, spatial spread of the noise can be suppressed. As a result, the noise is not easy to perceive.
Like a FlashPix file proposed by Eastman Kodak Co., a file format enabling storage of data sets having different natures in a file has also been proposed. Hierarchical data decomposed into multiple resolutions or density resolutions can be stored in such a file according to the FlashPix standard.
By decomposing the image data into multiple resolutions or density resolutions, the image data can be reconstructed from data at a plurality of levels having different resolutions or density resolutions.
Furthermore, it is possible to construct image data representing an image from data at a plurality of levels representing the same image each having different quality when the image is reproduced. In other words, image data obtained by decompressing image data having been compressed in a reversible manner have no degradation, while image data obtained by decompressing image data having been compressed in an irreversible manner have degradation depending on a sampling interval of the data. Therefore, quality of a reproduced image can be changed according to whether image data are compressed in a reversible manner or in an irreversible manner. Consequently, image data can be reconstructed from the data at a plurality of levels having different reproduced image quality.
When image data are constructed from data at a plurality of levels and stored in an image server in this manner, data at an appropriate resolution or density resolution or having appropriate quality of a reproduced image can be transferred to a client based on the client""s request, and the client""s request can be met.
Furthermore, a method of transferring image data to a terminal connected to an image server having means for storing an image data set in detail, that is, data at a high level (high resolution or density resolution, or high reproduced image quality) and for converting a level of the image to be output, instead of an image server storing image data at a plurality of levels, has been known. In this case, as has been described above, data at an appropriate level can be transferred to the client based on the request by the client.
However, the level of the data requested by a client is different depending on a user of the terminal, the type of the terminal, and the usage of the image data. For example, the level of an image requested is different between the cases of a diagnostic purpose such as a diagnosis in detail, a confirmation purpose such as confirmation of an outline, and taking a view of an outline image such as subtraction at an interval. Furthermore, the level requested is different between wards or doctors, and each has a predetermined level in most cases.
For this reason, it is necessary to specify the level of data desired by a client by inputting the level whenever image data transfer is requested. As a result, an operation for requesting data transfer is very troublesome.
The present invention has been created based on consideration of the above problems. An object of the present invention is to provide a method and an apparatus for easily transferring image data at a desired level to a terminal without causing a problem on a client, and a computer-readable recording medium storing a program to cause a computer to execute the method.
A data transfer method of the present invention is a method of transferring image data to a terminal connected to an image server from the server storing image data including a plurality of levels or comprising means for storing image data and for converting a level of an image to be output, and the method comprises the steps of:
obtaining information regarding the terminal; and
transferring to the terminal the image data at a level appropriate for the terminal, based on the information regarding the terminal.
The xe2x80x9clevel of an imagexe2x80x9d herein referred to may be different depending on a request by the terminal, and the level means resolution and/or density resolution, specifically.
The xe2x80x9cimage data including a plurality of levelsxe2x80x9d means to construct image data from a plurality of data sets each having different resolution and/or density resolution obtained by decomposing image data into multiple resolutions and/or density resolutions. Alternatively, the image data comprises sets of image data each having different reproduced image quality resolution and/or density resolution, as in the case where the image data comprise data sets each having different reproduced image quality such as reversibly compressed data and irreversibly compressed data. These levels may be used solely or in a combination.
The xe2x80x9cinformation regarding the terminalxe2x80x9d means information obtained from the terminal, that is, information corresponding to the level of the image requested by the terminal More specifically, the information regarding the terminal means information regarding a terminal user input from the terminal, information specific to the terminal, and information input from the terminal regarding usage of the image data, for example.
The xe2x80x9cinformation regarding a terminal userxe2x80x9d means any information by which the terminal user can be identified. More specifically, the information means the name and ID information input by the user, ID information obtained by reading an ID card, audio information of the terminal user, a fingerprint or a handprint of the user, information obtained by recognizing the face of the user, and information regarding the section the user belongs to, for example. These kinds of information can be used solely or in combination.
The xe2x80x9cinformation specific to the terminalxe2x80x9d means information by which the terminal can be identified or information indicating a level of an image which can be displayed on the terminal. For example, the IP address specific to the terminal, the type number of the terminal, and a data representation ability of the terminal can be listed as the information specific to the terminal.
The xe2x80x9cinformation regarding the usage of the image dataxe2x80x9d means not only information regarding complexity of the image and information regarding a transfer rate, but also information regarding a diagnosis menu and a photographing menu, and information regarding the dosage of radiation used upon photographing a radiation image, in the case of the images used in the field of medicine.
When the complexity of an image is increased, the image can be observed in detail if the image is reproduced by using data at a higher level. Therefore, in the case where the terminal user inputs, by using the terminal, an instruction to transfer data according to the complexity, xe2x80x9cthe information regarding complexity of an imagexe2x80x9d means information to cause an image server to transfer image data at a level corresponding the complexity of the image.
The xe2x80x9cinformation regarding a transfer ratexe2x80x9d means information to instruct an image server to transfer the image data at a level whose transmission can be completed within a predetermined amount of time depending on a band width of a transfer path, in the case where the user inputs an instruction to transfer the data based on the transfer rate.
Furthermore, when progress observation is carried out, high level data are necessary, since information in detail regarding a patient""s latest image data are needed. However, demands for high level image data of the past are not high. Therefore, xe2x80x9cinformation regarding a diagnosis menuxe2x80x9d means information to instruct transfer of high level image data for a latest image and to instruct transfer of moderate level image data for an image in the past, in the case where a progress observation purpose has been input.
Moreover, high level image data are necessary in the case where a minute tumor is diagnosed from a chest radiation image, while a demand for such high level image data as those for a chest radiation image is not so high in the case where a radiation image of a broken bone of a leg or an arm is needed. Therefore, the xe2x80x9cinformation regarding a photographing menuxe2x80x9d means information to instruct transfer of high level image data for a radiation image obtained by photographing a chest and transfer of a moderate level image data for a radiation image of a broken bone of a leg or an arm, in the case where a terminal user inputs from the terminal an instruction to transfer data based on a photographed portion.
For an important image, photographing is carried out with high dosage of radiation in order to reduce noise. Therefore, xe2x80x9cinformation regarding dosagexe2x80x9d means information to instruct an image server to transfer high level image data such that the data enable observation of an image in detail when the dosage is higher, in the case where a terminal user inputs an instruction to transfer data based on the dosage.
A data transfer apparatus of the present invention is an apparatus for transferring image data to a terminal connected to an image server from the server storing image data at a plurality of levels or comprising means for storing image data and for converting a level of an image to be output, and the apparatus comprises:
terminal information obtaining means for obtaining information regarding the terminal; and
transfer means for transferring to the terminal the image data at a level appropriate for the terminal, based on the information regarding the terminal.
The data transfer method of the present invention may be provided as a computer-readable recording medium storing a program to cause a computer to execute the method.
According to the present invention, since image data at a level appropriate for the terminal are transferred based on the terminal information, when a terminal user inputs from the terminal an instruction to request image data transfer, image data at a desired level in accordance with the terminal user, the terminal, the usage of the image and the like can be transferred without specifying the level. Therefore, image data at a desired level can be transferred easily without a troublesome operation for specifying the level.